Flat-Panel-Display becomes the main stream in the display technology which develops toward higher frame frequency, higher resolution and narrower frame in recent years. The integrated display driver circuit refers to the gate drive circuit and the data driver circuit and other peripheral circuits with thin-film transistor (TFT) in the form of pixel TFT—from production on the display panel. Compared with the traditional process, using integrated display driven approach not only reduces the number of peripheral driver chips and packer procedures, reduce costs, but also makes the peripheral more slim monitor, the display module more compact, mechanical and electrical reliability resistance is enhanced.
In the integrated display driver circuit, the shift register is the important circuit module which achieves the integrated gate (row) driving circuit and the integrated data (column) driving circuit. Based on the shift register with the amorphous silicon TFT, one limitation is low drift mobility so that it is hard to promote the work frequency; the other limitation is the larger circuit area, so the requirement is harder and harder to satisfy in the practical way. Because the oxide semiconductor TFT has the advantages of smooth characteristic, high drift mobility, good stability and low cost manufacture, it becomes the TFT technology of general concern in the recent year. The integrated shift register circuit of the oxide semiconductor also has some elemental research.
In the existing circuit structure of the shift register, the capacitance bootstrapping effect is used to enhance the driving power of the transistor, such that further to speed up the charging of the output load. Because of the reason of the leakage existing in the internal circuit or the larger size of the controlling capacitance of the driving transistor in the traditional shift register circuit, the control electrode of the driving transistor can bootstrap to the high potential. The raising time of the output pulse is longer to enhance limitation of the work frequency of the circuit. Especially, when the temperature is high and the threshold value of TFT is smaller, the effect will be more serious. On the other side, when the output load of the shift register is higher, the traditional shift register needs the large size pull-down tube to charge the load so the circuit area is usually large. It is not easily applied in the high resolution display.